

The episode opens in Africa with the scene of a lion chasing a leopard. As the two fight, a huge gorilla enters. Broken shackles dangle from the gorilla's wrists. Speed is flying to Africa. Professor Robert Carnivoré is sitting next to Speed on the plane. He relates the story of a huge monster that lives near the mountain they're flying over. Speed will be participating in the Trans-Africa Grand Prix, a race which crosses the continent of Africa. He checked out the course and is on his way to Nairobi where the race will start. The pilot and co-pilot point weapons at the professor and Speed. They are exiles from the nation of Bangdabongo. Carnivoré is also an ex-pat from Bangdabongo. The men need the professor's help to liberate their country which was taken over 20 years before. The men and the professor get parachutes to jump out safely. Speed is tied up. As the plane plummets earthward, Speed snaps the ropes. He dons a parachute and jumps out at the last moment. Down on the ground, S
After winning a practice race, Speed Racer is offered a position on a team set to race in the Grand Prix. The company who employs his father, Pops Racer, a top engineer, owns the team. However, Speed declines because Pops doesn't want him to become a pro. Meanwhile, Pops quits when his plans to improve the Mach 5 are rejected. While Pops and Speed are driving home, a gang of motorcycle racers steals their plans. Trixie, in her helicopter, runs the gang off the road and the plans are recovered. Back at the cyclist headquarters, bad guy Acey Ducey shows up and offers to get the plans for "5,000 clams." He confronts Pops but leaves empty-handed as Pops has hidden the designs on the Mach 5's windshield using invisible ink. Deciding to sell the Mach 5 so Pops can rebuild the engine, Speed visits Sparky, who suggests that Speed enter the Sword Mountain Race for a $5,000 prize. While Speed takes the Mach 5 out for a road test, "dirty driver" Duggery rams the car, causing it to blow a tire.
Speed resumes the Sword Mountain Race, neck and neck with Duggery. Ace and his gang approach from the opposite direction. Speed swerves off the road and uses his rotary saws to cut a path through the overgrown terrain. Trixie creates a temporary distraction, bombing the gang with smoke flares from her plane. At a cross-road, Duggery decides to take a "shortcut." Speed knows that the road leads to a dangerous volcano and sets out to rescue him. Meanwhile, Ace and his gang fire at Trixie. The plane plummets but Trixie escapes. At the edge of the volcano, Duggery is thrown from his car, and left dangling from a rock. Speed also ends up on a rock shelf after trying to rescue his competitor. They manage to reach safety but find that the gang surrounds the Mach 5, with Trixie taken hostage. Spritle and Chim Chim, who have hidden in the Mach 5's trunk, throw rocks at the gang while Speed, Duggery, and Trixie fight them off. Ace takes off in the Mach 5. Speed follows in hot pursuit.